1. Field of the Invention
This invention relates to silicone aqueous emulsions which yield an elastomer upon removal of the water.
2. Background Information
Silicone aqueous emulsions of various types have been disclosed over the years. For example, Canadian Pat. No. 862,183, issued Jan. 26, 1971, discloses a composition and process for treating fiber glass to impart a firmer hand. The composition consists essentially of a liquid hydroxy endblocked dimethylsiloxane polymer, a silane of the formula R.sub.n SiR'.sub.4-n wherein R is a hydrocarbon or substituted hydrocarbon radical containing from 1 to 20 carbon atoms, and a siloxane condensation catalyst. Included in a long list of suitable R radicals on the silane are amino containing ones. There is no criticality assigned to the choice of radical or to the method of emulsification.
A composition useful as a caulk is described in U.S. Pat. No. 3,817,894, issued June 18, 1974. The composition consists essentially of a siloxane copolymer, water, a filler, surfactants, and an aminofunctional silane. The aminofunctional silane is stated to function as a crosslinking agent and as curing catalyst for the siloxane copolymer.
An organopolysiloxane latex composition crosslinked by organofunctional trialkoxysilanes are useful for binding fiber glass fibers as disclosed in U.S. Pat. No. 4,228,054, issued Oct. 14, 1980. The composition is prepared by dissolving a surfactant in water, adding a cyclic organosiloxane and the organofunctional trialkoxysilane, then emulsifying and heating to obtain a high molecular weight organopolysiloxane, which is cooled and neutralized to give the product.
Japanese Kokai publication No. 83-69250, published Apr. 25, 1983, describes a silicone aqueous emulsion composition which consists of (A) an anionic silicone emulsion, (B) a homogeneous dispersion of amino-functional silane or partial hydrolyzate and colloidal silica, and (C) a curing catalyst. The aminofunctional silane is of the formula R"Si(OR').sub.4-n where R" is amino-functional, R' is an alkyl, acyl, etc. group, and n is 1,2,3,or 4.
U.S. Pat. No. 4,496,687, issued Jan. 29, 1985, describes an organopolysiloxane-containing aqueous emulsion composition prepared by blending (A) an aqueous emulsion of an organopolysiloxane having silicon-bonded hydroxy groups and emulsified in water by use of an anionic surface active agent, (B) a mixture of a reaction product of a carboxylic acid anhydride with an amino-functional organosilane and a colloidal silica in the form of an aqueous emulsion and (C) a curing catalyst. The composition is stated to be very stable and storable over a long period of time. It cures into a rubbery elastomer having good adhesion to the surface of the substrate on which it is dried and cured.
U.S. Pat. No. 4,412,035, issued Oct. 25, 1983, relates to a silicone cationic emulsion composition of a polydiorganosiloxane containing amino, epoxy, and hydroxy groups as functional groups, and which may be used as a releasing agent, stripping agent, paint component, and anti-foaming agent. A reaction product of a silanol containing polydiorganosiloxane, an amine functional silane, and an epoxy functional silane is emulsion polymerized with a cyclic siloxane, a quaternary ammonium salt surfactant and water.
British patent application No. 2,152,521 A, published Aug. 7, 1985, discloses a method for producing aminoalkylsiloxane polymers of high molecular weight by hydrolyzing a difunctional aminoalkylsilane prior to reaction with hydroxy terminated siloxane oligomers.
U.S. Pat. No. 4,535,109, issued Aug. 13, 1985, describes a method of producing silicone aqueous emulsion compositions. The method prepares an emulsion of polydiorganosiloxane, colloidal silica, curing catalyst, emulsifier, and water. After a period of ripening, an amino-functional silane or its partial hydrolyzate is added to give superior gloss, good adhesion to substrates, and a rustproof coating.